The present invention relates to air bags for protecting a vehicle occupant.
The preferred embodiment of the present invention is described in the context of a curtain air bag that is deployable from a roof rail of the vehicle. The prior art illustrates curtain air bags with a peripheral border fastened directly or indirectly to a roof rail. In one variation a tab is sewn to the top of the border and a fastener is inserted through the tab into the roof rail. The tab can also be an integral part of the border region or main panel of the air bag. It is not necessary to use a tab, for example the top of the border region may include one or more fastener holes and a fastener is received through each hole. When an air bag inflates it does so rapidly, moving a mass of material from a folded configuration to its expanded, inflated configuration. As the air bag inflates the various stresses are created in the air bag at the point of attachment to the vehicle; generally at or about the mounting hole or fastener. The present invention substantially reduces these stresses providing for a more robust airbag.
More specifically the invention comprises: an air bag for use in a vehicle comprising: a border region having a top situated about at least one inflatable region; the top of the border region configured to be secured directly or indirectly to a portion of the vehicle or component of the vehicle; wherein the border region includes at least one slit. The inclusion of one or more slits permits the top of the border region to deform as the air bag deploys to its inflated condition; as the slit is stretched and opens, energy is absorbed and less stress is seen on those portions secured to the vehicle or to a vehicle component. An additional benefit of the present invention is that the incorporation of the slits permits the bottom (or generally an opposite end, side or region) of the air bag to extend further away from the mounting locations than could be achieved without the slits thereby increasing the effective size of the air bag. This feature permits a smaller air bag to replace a larger prior art air bag.